PROJECT SUMMARY Microarray patches (MAPs), also known as microneedle patches, are a novel, needle-free delivery technology in development for drugs and vaccines. MAPs contain an array of dissolving micron-scale projections and are applied like a bandage, painlessly piercing the stratum corneum to facilitate intradermal delivery. Due to their ease of use and acceptability, MAPs can potentially improve adherence to treatment, particularly for children. We propose to develop a MAP containing long-acting antiretrovirals as an age-appropriate, long-acting drug delivery system to treat pediatric HIV infection, with a particular focus on suitability for use in young children. The MAP would be designed to require a short wear time (less than 1 hour) and deliver enough drug to provide a monthly (or less frequent) dosing regimen. In contrast to other long-acting dosage forms, such as injectables and implants, the MAP would be painless and could be administered at home by parents or caregivers. The first phase of the project will focus on defining pediatric MAP requirements and optimizing antiretroviral MAP formulations. In the first two years, the project team plans to: 1. Define target product profile targets and preferred user characteristics, identify stakeholder needs, and evaluate potential acceptability to inform product development. 2. Determine MAP parameters through physiologically-based pharmacokinetic modeling. 3. Design, manufacture, and characterize nanosuspension-loaded dissolving MAPs. Assuming promising results from the first phase, during the second phase of the project we will focus on verifying MAP performance in preclinical and end user studies. In the last three years, the project team plans to: 4. Assess in vivo drug delivery and pharmacokinetic extrapolation. 5. Assess pharmacokinetics and antiviral efficacy in non-human primates. 6. Conduct user-centered design development of MAP prototypes, conduct a risk analysis, and assess end user acceptability.